National Academy of Sciences Reports Four Percent of Death Row Inmates are Innocent

In a study released today, the National Academy of Sciences reports that at least 4.1 percent of defendants sentenced to death in the United States are innocent. The article, “Rate of False Conviction of Criminal Defendants who are Sentenced to Death,” reveals that the number of innocent people is likely more than double the number of those actually exonerated and freed from death row.

The groundbreaking research reported that although 138 death row inmates have been exonerated and released after proving innocence, many other innocent capital defendants are missed if they are removed from death row or have their sentences reduced to life in prison after appeals. Once the threat of wrongful execution is removed, less time and resources are devoted to seeking out cases of possible innocence.

Since some of the prisoners with reduced sentences could have died behind bars while serving a life sentence, the researchers used a statistical technique called survival analysis to yield an estimate of the percentage of death row defendants who would be exonerated if they had all remained indefinitely on death row and therefore subject to the exacting process for identifying innocent defendants that is applied to those who remain under threat of execution. The researchers concluded that their 4.1 percent finding is a conservative estimate.